Hans Halvorson
Biographic Data
| ID | 974128 |
|---|---|
| NAME | Hans Halvorson |
| GIVEN NAMES | Hans |
| FAMILY NAME | Halvorson |
| SIGNATURE | HALVORSON H |
| AFFILIATIONS | Princeton University |
| ORCID | 0000-0003-3022-2344 |
| VERIFIED | Yes |
| TOTAL WORKS | 23 |
| TOTAL CITATIONS | 121 |
| AUTHOR COUNT | 23 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 2001 |
| LATEST PUBLICATION YEAR | 2026 |
| H-INDEX | 5 |
Deterministic Theories
Determinism is (roughly) the thesis that the past determines the future. But efforts to define it precisely have exposed deep methodological disagreements. Standard possible‐worlds formulations of determinism presuppose an “agreement” relation between worlds, but this relation can be understood in multiple ways, none of which is particularly clear. We critically examine the proliferation of definitions of determinism in the recent literature, arg…
Fundamental Physics and Middle-Sized Dry Goods
I consider the debate between those who believe in microphysical reductionism, and those who believe in the irreducibility of macroscopic objects. I consider, in particular, recent arguments that physics itself refutes the hypothesis of reductionism – from, among others, George Ellis and Barbara Drossel. I raise some questions about the effectiveness of these arguments, and I suggest that this debate is based on an unclear, but emotionally fraugh…
Determinism and Asymmetry in General Relativity
This paper concerns the question of which collections of general relativistic spacetimes are deterministic relative to which definitions. We begin by considering a series of three definitions of increasing strength due to Belot (1995). The strongest of these definitions is particularly interesting for spacetime theories because it involves an asymmetry condition called ``rigidity'' that has been studied previously in a different context (Geroch 1…
Closing the Hole Argument
The hole argument purportedly shows that spacetime substantivalism implies a pernicious form of indeterminism. Here we attempt to answer the question: what is the mathematical fact that is supposed to underwrite the hole argument? We identify two relevant mathematical claims. The first claim is trivially true, and Weatherall (2018) has convincingly argued that it cannot support the hole argument. The second claim would support the hole argument, …
What Philosophy of Science has to Offer to Theology
In this text, I explore the intertwined relationship between philosophy of science and theology, and the challenges they both encounter in the academic realm. While theology is struggling to maintain its relevance, philosophy of science has gained recognition and offers valuable insights to theologians. I argue that theologians can benefit from engaging with the content and methods of specific sciences, and philosophers of science can help affirm…
John Bell on ‘Subject and Object’: An Exchange
Mutual translatability, equivalence, and the structure of theories
The Logic in Philosophy of Science
Major figures of twentieth-century philosophy were enthralled by the revolution in formal logic, and many of their arguments are based on novel mathematical discoveries. Hilary Putnam claimed that the Löwenheim-Skølem theorem refutes the existence of an objective, observer-independent world; Bas van Fraassen claimed that arguments against empiricism in philosophy of science are ineffective against a semantic approach to scientific theories; W. V.…
Logic in Philosophy of Science
Quine’s conjecture on many-sorted logic
The Conventionality of Parastatistics
Nature seems to be such that we can describe it accurately with quantum theories of bosons and fermions alone, without resort to parastatistics. This has been seen as a deep mystery: paraparticles make perfect physical sense, so why don’t we see them in nature? We consider one potential answer: every paraparticle theory is physically equivalent to some theory of bosons or fermions, making the absence of paraparticles in our theories a matter of c…
How is spontaneous symmetry breaking possible? Understanding Wigner's theorem in light of unitary inequivalence
The Semantic View, If Plausible, Is Syntactic
Halvorson argues that the semantic view of theories leads to absurdities. Glymour shows how to inoculate the semantic view against Halvorson’s criticisms, namely, by making it into a syntactic view of theories. I argue that this modified semantic-syntactic view cannot do the philosophical work that the original “language-free” semantic view was supposed to do
What Scientific Theories Could Not Be
According to the semantic view of scientific theories, theories are classes of models. I show that this view—if taken literally—leads to absurdities. In particular, this view equates theories that are distinct, and it distinguishes theories that are equivalent. Furthermore, the semantic view lacks the resources to explicate interesting theoretical relations, such as embeddability of one theory into another. The untenability of the semantic view—a…
Antimatter
The nature of antimatter is examined in the context of algebraic quantum field theory. It is shown that the notion of antimatter is more general than that of antiparticles. Properly speaking, then, antimatter is not matter made up of antiparticles—rather, antiparticles are particles made up of antimatter. We go on to discuss whether the notion of antimatter is itself completely general in quantum field theory. Does the matter–antimatter distincti…
On information-theoretic characterizations of physical theories
Complementarity of representations in quantum mechanics
Robert K. Clifton 1964–2002
On quanta, mind, and matter: Hans Primas in Context
No Place for Particles in Relativistic Quantum Theories
David Malament (1996) has recently argued that there can be no relativistic quantum theory of (localizable) particles. We consider and rebut several objections that have been made against the soundness of Malament's argument. We then consider some further objections that might be made against the generality of Malament's conclusion, and we supply three no-go theorems to counter these objections. Finally, we dispel potential worries about the coun…
Entanglement and Open Systems in Algebraic Quantum Field Theory
Reeh-Schlieder Defeats Newton-Wigner: On Alternative Localization Schemes in Relativistic Quantum Field Theory
Many of the “counterintuitive” features of relativistic quantum field theory have their formal root in the Reeh-Schlieder theorem, which in particular entails that local operations applied to the vacuum state can produce any state of the entire field. It is of great interest then that I. E. Segal and, more recently, G. Fleming (in a paper entitled “Reeh-Schlieder meets Newton-Wigner”) have proposed an alternative “Newton-Wigner” localization sche…
Are Rindler Quanta Real? Inequivalent Particle Concepts in Quantum Field Theory
Philosophical reflection on quantum field theory has tended to focus on how it revises our conception of what a particle is. However, there has been relatively little discussion of the threat to the ‘reality’ of particles posed by the possibility of inequivalent quantizations of a classical field theory, i.e. inequivalent representations of the algebra of observables of the field in terms of operators on a Hilbert space. The threat is that each r…
What Scientific Theories Could Not Be
According to the semantic view of scientific theories, theories are classes of models. I show that this view—if taken literally—leads to absurdities. In particular, this view equates theories that are distinct, and it distinguishes theories that are equivalent. Furthermore, the semantic view lacks the resources to explicate interesting theoretical relations, such as embeddability of one theory into another. The untenability of the semantic view—a…
The Semantic View, If Plausible, Is Syntactic
Halvorson argues that the semantic view of theories leads to absurdities. Glymour shows how to inoculate the semantic view against Halvorson’s criticisms, namely, by making it into a syntactic view of theories. I argue that this modified semantic-syntactic view cannot do the philosophical work that the original “language-free” semantic view was supposed to do
No Place for Particles in Relativistic Quantum Theories
David Malament (1996) has recently argued that there can be no relativistic quantum theory of (localizable) particles. We consider and rebut several objections that have been made against the soundness of Malament's argument. We then consider some further objections that might be made against the generality of Malament's conclusion, and we supply three no-go theorems to counter these objections. Finally, we dispel potential worries about the coun…
Are Rindler Quanta Real? Inequivalent Particle Concepts in Quantum Field Theory
Philosophical reflection on quantum field theory has tended to focus on how it revises our conception of what a particle is. However, there has been relatively little discussion of the threat to the ‘reality’ of particles posed by the possibility of inequivalent quantizations of a classical field theory, i.e. inequivalent representations of the algebra of observables of the field in terms of operators on a Hilbert space. The threat is that each r…
Antimatter
The nature of antimatter is examined in the context of algebraic quantum field theory. It is shown that the notion of antimatter is more general than that of antiparticles. Properly speaking, then, antimatter is not matter made up of antiparticles—rather, antiparticles are particles made up of antimatter. We go on to discuss whether the notion of antimatter is itself completely general in quantum field theory. Does the matter–antimatter distincti…
Quine’s conjecture on many-sorted logic
Mutual translatability, equivalence, and the structure of theories
Reeh-Schlieder Defeats Newton-Wigner: On Alternative Localization Schemes in Relativistic Quantum Field Theory
Many of the “counterintuitive” features of relativistic quantum field theory have their formal root in the Reeh-Schlieder theorem, which in particular entails that local operations applied to the vacuum state can produce any state of the entire field. It is of great interest then that I. E. Segal and, more recently, G. Fleming (in a paper entitled “Reeh-Schlieder meets Newton-Wigner”) have proposed an alternative “Newton-Wigner” localization sche…
The Conventionality of Parastatistics
Nature seems to be such that we can describe it accurately with quantum theories of bosons and fermions alone, without resort to parastatistics. This has been seen as a deep mystery: paraparticles make perfect physical sense, so why don’t we see them in nature? We consider one potential answer: every paraparticle theory is physically equivalent to some theory of bosons or fermions, making the absence of paraparticles in our theories a matter of c…
Closing the Hole Argument
The hole argument purportedly shows that spacetime substantivalism implies a pernicious form of indeterminism. Here we attempt to answer the question: what is the mathematical fact that is supposed to underwrite the hole argument? We identify two relevant mathematical claims. The first claim is trivially true, and Weatherall (2018) has convincingly argued that it cannot support the hole argument. The second claim would support the hole argument, …
Entanglement and Open Systems in Algebraic Quantum Field Theory
Reeh-Schlieder Defeats Newton-Wigner: On Alternative Localization Schemes in Relativistic Quantum Field Theory
Many of the “counterintuitive” features of relativistic quantum field theory have their formal root in the Reeh-Schlieder theorem, which in particular entails that local operations applied to the vacuum state can produce any state of the entire field. It is of great interest then that I. E. Segal and, more recently, G. Fleming (in a paper entitled “Reeh-Schlieder meets Newton-Wigner”) have proposed an alternative “Newton-Wigner” localization sche…
Are Rindler Quanta Real? Inequivalent Particle Concepts in Quantum Field Theory
Philosophical reflection on quantum field theory has tended to focus on how it revises our conception of what a particle is. However, there has been relatively little discussion of the threat to the ‘reality’ of particles posed by the possibility of inequivalent quantizations of a classical field theory, i.e. inequivalent representations of the algebra of observables of the field in terms of operators on a Hilbert space. The threat is that each r…
On quanta, mind, and matter: Hans Primas in Context
No Place for Particles in Relativistic Quantum Theories
David Malament (1996) has recently argued that there can be no relativistic quantum theory of (localizable) particles. We consider and rebut several objections that have been made against the soundness of Malament's argument. We then consider some further objections that might be made against the generality of Malament's conclusion, and we supply three no-go theorems to counter these objections. Finally, we dispel potential worries about the coun…
Robert K. Clifton 1964–2002
On information-theoretic characterizations of physical theories
Complementarity of representations in quantum mechanics
Antimatter
The nature of antimatter is examined in the context of algebraic quantum field theory. It is shown that the notion of antimatter is more general than that of antiparticles. Properly speaking, then, antimatter is not matter made up of antiparticles—rather, antiparticles are particles made up of antimatter. We go on to discuss whether the notion of antimatter is itself completely general in quantum field theory. Does the matter–antimatter distincti…
What Scientific Theories Could Not Be
According to the semantic view of scientific theories, theories are classes of models. I show that this view—if taken literally—leads to absurdities. In particular, this view equates theories that are distinct, and it distinguishes theories that are equivalent. Furthermore, the semantic view lacks the resources to explicate interesting theoretical relations, such as embeddability of one theory into another. The untenability of the semantic view—a…
How is spontaneous symmetry breaking possible? Understanding Wigner's theorem in light of unitary inequivalence
The Semantic View, If Plausible, Is Syntactic
Halvorson argues that the semantic view of theories leads to absurdities. Glymour shows how to inoculate the semantic view against Halvorson’s criticisms, namely, by making it into a syntactic view of theories. I argue that this modified semantic-syntactic view cannot do the philosophical work that the original “language-free” semantic view was supposed to do
The Conventionality of Parastatistics
Nature seems to be such that we can describe it accurately with quantum theories of bosons and fermions alone, without resort to parastatistics. This has been seen as a deep mystery: paraparticles make perfect physical sense, so why don’t we see them in nature? We consider one potential answer: every paraparticle theory is physically equivalent to some theory of bosons or fermions, making the absence of paraparticles in our theories a matter of c…
Quine’s conjecture on many-sorted logic
The Logic in Philosophy of Science
Major figures of twentieth-century philosophy were enthralled by the revolution in formal logic, and many of their arguments are based on novel mathematical discoveries. Hilary Putnam claimed that the Löwenheim-Skølem theorem refutes the existence of an objective, observer-independent world; Bas van Fraassen claimed that arguments against empiricism in philosophy of science are ineffective against a semantic approach to scientific theories; W. V.…
Logic in Philosophy of Science
Mutual translatability, equivalence, and the structure of theories
What Philosophy of Science has to Offer to Theology
In this text, I explore the intertwined relationship between philosophy of science and theology, and the challenges they both encounter in the academic realm. While theology is struggling to maintain its relevance, philosophy of science has gained recognition and offers valuable insights to theologians. I argue that theologians can benefit from engaging with the content and methods of specific sciences, and philosophers of science can help affirm…
John Bell on ‘Subject and Object’: An Exchange
Fundamental Physics and Middle-Sized Dry Goods
I consider the debate between those who believe in microphysical reductionism, and those who believe in the irreducibility of macroscopic objects. I consider, in particular, recent arguments that physics itself refutes the hypothesis of reductionism – from, among others, George Ellis and Barbara Drossel. I raise some questions about the effectiveness of these arguments, and I suggest that this debate is based on an unclear, but emotionally fraugh…
Determinism and Asymmetry in General Relativity
This paper concerns the question of which collections of general relativistic spacetimes are deterministic relative to which definitions. We begin by considering a series of three definitions of increasing strength due to Belot (1995). The strongest of these definitions is particularly interesting for spacetime theories because it involves an asymmetry condition called ``rigidity'' that has been studied previously in a different context (Geroch 1…
Closing the Hole Argument
The hole argument purportedly shows that spacetime substantivalism implies a pernicious form of indeterminism. Here we attempt to answer the question: what is the mathematical fact that is supposed to underwrite the hole argument? We identify two relevant mathematical claims. The first claim is trivially true, and Weatherall (2018) has convincingly argued that it cannot support the hole argument. The second claim would support the hole argument, …
Deterministic Theories
Determinism is (roughly) the thesis that the past determines the future. But efforts to define it precisely have exposed deep methodological disagreements. Standard possible‐worlds formulations of determinism presuppose an “agreement” relation between worlds, but this relation can be understood in multiple ways, none of which is particularly clear. We critically examine the proliferation of definitions of determinism in the recent literature, arg…
Philosophy (12 works) · Epistemology (11 works) · Physics (10 works) · Quantum Mechanics and Applications (10 works) · Mathematics (9 works) · Philosophy and History of Science (8 works) · Quantum mechanics (8 works) · Theoretical physics (8 works) · Computer Science (7 works) · Pure mathematics (6 works)